Aircraft engines and auxiliary power units are known to include turbines and compressors which rotate about a central shaft at high rotational speeds. Although modern gas turbine engines and auxiliary power units can perform for thousands of hours without any significant malfunction, circumstances have arisen where the rotational hub of a turbine or impeller can burst.
As it is desirable to contain rotor fragments projected by a burst within the shortest distance possible, containment elements are generally provided in close proximity of the rotor for that purpose. However, these containment elements, as well as other engine elements located near the rotor, can transmit substantially large loads to the adjoining structures when struck by a fragment of a burst rotor. As such, even when the fragments are contained by the containment elements, damage from substantial loads produced by the impact of the fragments on the containment elements can propagate through the engine structure, and hence to the aircraft structure, for example through the joints interconnecting the various engine elements.
Accordingly, improvements are desirable.